Ultra-fast computation of electronic spectra for large systems by tight-binding based simplified Tamm-Dancoff approximation (sTDA-xTB)
Ultra-fast computation of electronic spectra for large systems by tight-binding based simplified Tamm-Dancoff approximation (sTDA-xTB)
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DOI：
10.1063/1.4959605
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发表时间：
2016-08-07
影响因子：
4.4
通讯作者：
Bannwarth, Christoph
中科院分区：
文献类型：
--
作者：
Grimme, Stefan;Bannwarth, Christoph
研究了基于Tamm-Dancoff近似的含时密度泛函方法的计算瓶颈[ S。格里姆，J.Chem.Phys.138，244104（2013）]中所述的用于计算大型系统的电子光谱的方法是确定基态Kohn-Sham轨道和本征值。这将这种处理限制在具有几百个原子的单一结构上，因此，e。例如，在一个实施例中，通常不可能沿柔性系统的分子动力学轨迹沿着取样或计算发色团聚集体。这项工作的目的是解决这个问题，通过一个专门设计的半经验紧束缚（TB）程序类似于建立良好的自洽电荷密度泛函TB计划。新的特殊用途的方法提供了轨道和轨道能量的混合密度泛函字符的后续和基本上未修改的sTDA程序。与许多以前的半经验激发态方法相比，该方法的一个优点是在非正交的扩展原子轨道基础上解决了一般本征值问题，从而获得了正确的占据/虚轨道能量分裂以及Rydberg能级。新模型成功的一个关键思想是，原子电荷的确定（描述有效的电子-电子相互作用）和单粒子谱是解耦的，并通过两个不同的参数化哈密顿量/基组进行处理。三对角化步骤的复合程序可以常规计算宽范围的电子光谱（0-8 eV）的计算时间内的系统组成的500-1000个原子的准确度典型的标准时间依赖密度泛函理论（0.3-0.5 eV的平均误差）。本文介绍了一种基于耦合簇和密度泛函计算的H-Zn（包括过渡金属）元素的参数化方法。被称为sTDA-xTB的方法的准确性是第一基准的垂直激发能量的开壳层和闭壳层系统相比，其他半经验的方法和应用于电子光谱学中的示例性问题。作为副产品的发展，一个强大的和有效的价电子TB方法的准确测定原子电荷，以及更准确的计算方案内的Tamm-Dancoff近似的偶极旋转强度。出版社：AIP Publishing
The computational bottleneck of the extremely fast simplified Tamm-Dancoff approximated ( sTDA) time-dependent density functional theory procedure [ S. Grimme, J. Chem. Phys. 138, 244104 ( 2013)] for the computation of electronic spectra for large systems is the determination of the ground state Kohn-Sham orbitals and eigenvalues. This limits such treatments to single structures with a few hundred atoms and hence, e. g., sampling along molecular dynamics trajectories for flexible systems or the calculation of chromophore aggregates is often not possible. The aim of this work is to solve this problem by a specifically designed semi-empirical tight binding ( TB) procedure similar to the well established self-consistent-charge density functional TB scheme. The new special purpose method provides orbitals and orbital energies of hybrid density functional character for a subsequent and basically unmodified sTDA procedure. Compared to many previous semi-empirical excited state methods, an advantage of the ansatz is that a general eigenvalue problem in a non-orthogonal, extended atomic orbital basis is solved and therefore correct occupied/virtual orbital energy splittings as well as Rydberg levels are obtained. A key idea for the success of the new model is that the determination of atomic charges ( describing an effective electron-electron interaction) and the one-particle spectrum is decoupled and treated by two differently parametrized Hamiltonians/basis sets. The three-diagonalization-step composite procedure can routinely compute broad range electronic spectra ( 0-8 eV) within minutes of computation time for systems composed of 500-1000 atoms with an accuracy typical of standard time-dependent density functional theory ( 0.3-0.5 eV average error). An easily extendable parametrization based on coupled-cluster and density functional computed reference data for the elements H-Zn including transition metals is described. The accuracy of the method termed sTDA-xTB is first benchmarked for vertical excitation energies of open-and closed-shell systems in comparison to other semi-empirical methods and applied to exemplary problems in electronic spectroscopy. As side products of the development, a robust and efficient valence electron TB method for the accurate determination of atomic charges as well as a more accurate calculation scheme of dipole rotatory strengths within the Tamm-Dancoff approximation is proposed. Published by AIP Publishing.